David Cameron’s failure last week to block Jean-Claude Juncker shows what he is up against in the renegotiation he is committed to if he returns to Downing Street after next May. Juncker is a symbol of the EU’s old ways. The Prime Minister wants it to have new ones. To improve his chances of achieving this outcome, he should send to Brussels as Britain’s next Commissioner a spokesman for reform – who by necessity needs to be a big hitter.

Today’s Sunday Times reports behind its paywall that David Willetts is interested in the post. Among those who the Prime Minister might send, this site’s readers have expressed support for Andrew Mitchell. We have already explained why Andrew Lansley, for all his good qualities, would not be the symbol of change that is needed. The paper’s report floats Michael Howard – Baron Howard of Lympne, as he now is – as a possible choice. He is certainly a heavy hitter.

So in terms of institutional experience is Martin Callanan. He is a former leader both of the Conservatives in the European Parliament and of the European Conservatives and Reformists Group – which he helped to build up from nothing to the third largest force in the European Parliament. Callanan is a Eurosceptic with inside knowledge of how the system works. He has always been loyal to Downing Street. The Parliament would be unlikely to block a former group leader.

Cameron’s inclination to send a long-time ally to Brussels is comprehensible. But if he wants to shake up the conventional way of doing business in Europe, he has a man to hand with a record of success.